The present invention relates primarily to flashlights, and in particular to a flashlight which can be conveniently held and operated by one hand.
Flashlights of varying sizes, shapes and switch configurations are well-known in the art. Most known flashlights utilize dry cell batteries as their source of electrical energy. Sometimes two or more such batteries are carried in series within a tube serving as a handle for the flashlight. Typically, an electrical current is established from one electrode of the battery through a conductor to a switch, then through another conductor to another electrode of the lamp bulb. After passing through the filament of the lamp bulb, the electrical current emerges to a second electrode of the lamp bulb in electrical contact with a conductor, which in turn is in electrical contact with the flashlight housing or another conductor positioned within and along the housing. The flashlight housing usually provides an electrical conducting path to an electrical conductor, generally a spring, in contact with the other electrode of the battery series. Actuation of the switch to complete the electrical circuit enables the electrical current to pass through the filament, thereby generating light which is typically focused by a reflector to form a beam of light.
Various flashlight designs have addresses improvements to the optical characteristics of the flashlight. For example, certain designs incorporate highly reflective, well-defined reflectors to enhance the quality of the light beam for a given battery configuration. Also, flashlights having a variable focus have been developed for various sizes of flashlights. The flashlight disclosed in my U.S. Pat. Nos. 4,577,263 and 4,658,336 illustrate a miniature flashlight having such improved characteristics. In that flashlight, the switching mechanism is incorporated into the head and insulator assemblies such that rotation of the head assembly relative to the housing, or barrel, will cause the flashlight to switch on and off, and further rotation will cause the reflector to move with respect to the bulb, thus varying the dispersion of the reflected light beam. In that flashlight, the head assembly also may be removed from the barrel and utilized as a base into which the tailcap and barrel may be inserted in its on condition for use as a table lamp.
One of the disadvantages of certain flashlights whether they be "fully-sized" flashlights or "miniature" flashlights is that these designs are such as to make the switching on and off and the focusing of the beam awkward, if not impossible to accomplish with the hand that is holding the flashlight by its barrel, or, handle. Because there exists a wide variety of uses for hand-held flashlights wherein the use would be facilitated by having a design such that the flashlight could be held in one hand, switched on and off and focused with that same hand, it may be seen as a deficiency in this art that heretofore no flashlight combining features to provide for such ease of operation has been developed. It is therefore desirable to provide a flashlight to be held in one hand and for which the switching and focusing operations may be performed with the hand holding the flashlight and without requiring that hand to change its grip on the flashlight while switching or focusing. It is also desirable in certain circumstances to provide a flashlight having "one-hand" operation where a particular focus after having been adjusted is maintained during the switching operation.